The overall objective of this research request for a Mentored Clinical Scientist Development Award (K08) is to explore environmental factors related to the development of obesity. In the past two decades, the prevalence of obesity has risen so dramatically worldwide as to indicate onset of a global obesity epidemic. Environmental factors that promote increased caloric intake and decreased energy expenditure are believed to underlie much of the present obesity trend. The goals of the research project are to examine and model how physical and social environmental factors contribute to the risk of obesity. The research aims of the proposal are: (1) To assemble a merged dataset consisting of individual-level clinical data for children and adults (with spatial location derived from addresses) and spatially indexed environmental and socioeconomic data; (2) To develop spatially based indices that describe physical environmental and social environmental factors that influence obesity for use in epidemiologic studies; and (3) To conduct cross-sectional multi-variate studies of normal weight, overweight, and obese study subjects utilizing the novel spatially based indices of physical environmental and social environmental factors. Aim 1 will be accomplished by extracting data from an electronic medical record system and by acquiring geographic data from a number of diverse sources including satellite photography, the US Census, and academic research centers. Aim 2 will be achieved by a multidisciplinary team of clinicians, statisticians, and urban planners who will design and compare indices of the physical and social environmental factors that provide opportunities for, or act as barriers to, physical activity and healthy diet. Aim 3 will be performed in conjunction with mentorship from nationally recognized experts in the fields of health services research, health behavior, and public policy. Geographic information systems will be used to identify environmental factors that are predictive of obesity. The identification of environmental variables associated with obesity has important implications for policy formation and targeted prevention efforts. This research request will provide the basis for an R01 research application to study an intervention that modifies environmental factors to prevent obesity.